<template>
  <!-- 布局容器 -->
  <el-container class="home-container">
    <!-- 头部 -->
    <el-header>
      <div>
        <img src="../assets/heima.png" />
        <span>电商后台管理系统</span>
      </div>
      <el-button type="info" @click="logout">退出</el-button>
    </el-header>
    <el-container>
      <!-- 侧边栏 -->
      <el-aside :width="isCollapse ? '64px' : '200px'">
        <!-- 按钮条 -->
        <div class="toggle-button" @click="toggleCollapce">|||</div>
        <!-- 侧边栏导航菜单 -->
        <el-menu 
        background-color="#333744" 
        text-color="#fff" 
        active-text-color="#409EFF" 
        unique-opened :collapse="isCollapse" 
        :collapse-transition='false'
        router 
        :default-active="activePath"
        >
          <!-- 一级菜单 -->
          <el-submenu :index="item.id + ''" v-for="item in menuList" :key="item.id">
            <!-- 一级菜单的模板区域 -->
            <template slot="title">
              <!-- 图标 -->
              <i :class="iconsObj[item.id]"></i>
              <!-- 文本 -->
              <span>{{item.authName}}</span>
            </template>
            <!-- 二级菜单 -->
            <el-menu-item 
            :index="'/' + subItem.path" 
            v-for="subItem in item.children" 
            :key="subItem.id"
            @click="saveNavState('/' + subItem.path)"
            >
                <!-- 二级菜单的模板区域 -->
                <template slot="title">
                <!-- 图标 -->
                <i class="el-icon-location"></i>
                <!-- 文本 -->
                <span>{{subItem.authName}}</span>
            </template>
            </el-menu-item>
          </el-submenu>
        </el-menu>
      </el-aside>
      <!-- 右侧内容主体 -->
      <el-main>
        <!-- 路由占位符 -->
        <router-view></router-view>
      </el-main>
    </el-container>
  </el-container>
</template>

<script>
export default {
  data() {
    return {
      menuList: [],
      iconsObj: {
        '125': 'iconfont icon-user',
        '103': 'iconfont icon-tijikongjian',
        '101': 'iconfont icon-shangpin',
        '102': 'iconfont icon-danju',
        '145': 'iconfont icon-baobiao'
      },
      // 控制是否折叠菜单
      isCollapse: false,
      // 被激活的链接地址
      activePath: '',
    };
  },
  methods: {
    // 退出功能 
    logout() {
      window.sessionStorage.clear();
      this.$router.push("/login");
    },

    // 获取菜单列表
    async getMenuList() {
      const {data: res} = await this.$http.get('menus')
      if (res.meta.status !== 200) return this.$message.error(res.meta.msg);
      this.menuList = res.data;
    },

    // 菜单的折叠
    toggleCollapce() {
      this.isCollapse = !this.isCollapse;
    },

    // 保存链接的激活状态
    saveNavState(activePath) {
       window.sessionStorage.setItem('activePath', activePath);
       this.activePath = activePath;
    }
  },
  // 钩子函数, 在组件创建之前调用里面的方法
  created() {
    this.getMenuList();
    this.activePath = window.sessionStorage.getItem('activePath');
  }
};
</script>

<style lang="less" scoped>
.home-container {
  height: 100%;
}
.el-header {
  background-color: #373d41;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-left: 0;
  color: #fff;
  font-size: 20px;
  > div {
    display: flex;
    justify-items: center;
    span {
      margin: 15px 0 0 15px;
    }
  }
}

.el-aside {
  background-color: #333744;
  .el-menu {border-right: none;}
}

.el-main {
  background-color: #eaedf1;
}

.iconfont {
  margin-right: 10px;
}
.toggle-button {
  line-height: 24px;
  font-size: 10px;
  background-color: #4a5064;
  text-align: center;
  cursor: pointer;
  letter-spacing: .2em;
  color: #fff;
}
</style>